add. uid2username to generate a mapping from user ids to usernames.
add. get_uname method.  Modularizes query on backend datastore.
mod. updated settings template to include db refs.
add. Docs on using input files with call_client.
mod. updated settings template to include db refs.
Merge pull request #1 from rfaulkner/master

UserID to Username script, update docs, update settings